GB2287542A - Sensorless measurement of electromagnetic actuator displacement device - Google Patents
Sensorless measurement of electromagnetic actuator displacement device Download PDFInfo
- Publication number
- GB2287542A GB2287542A GB9504314A GB9504314A GB2287542A GB 2287542 A GB2287542 A GB 2287542A GB 9504314 A GB9504314 A GB 9504314A GB 9504314 A GB9504314 A GB 9504314A GB 2287542 A GB2287542 A GB 2287542A
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- 238000006073 displacement reaction Methods 0.000 title claims abstract description 76
- 238000005259 measurement Methods 0.000 title description 8
- 238000002955 isolation Methods 0.000 claims abstract description 28
- 230000004907 flux Effects 0.000 claims abstract description 15
- 230000001419 dependent effect Effects 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 28
- 230000008569 process Effects 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 8
- 230000001133 acceleration Effects 0.000 claims description 6
- 238000005007 materials handling Methods 0.000 claims description 6
- 230000001276 controlling effect Effects 0.000 claims 3
- 238000003913 materials processing Methods 0.000 claims 2
- 230000001105 regulatory effect Effects 0.000 claims 1
- 238000000926 separation method Methods 0.000 claims 1
- 230000005284 excitation Effects 0.000 abstract description 7
- 230000008859 change Effects 0.000 abstract description 6
- 230000001360 synchronised effect Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 102000010029 Homer Scaffolding Proteins Human genes 0.000 description 2
- 108010077223 Homer Scaffolding Proteins Proteins 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011549 displacement method Methods 0.000 description 1
- 238000011143 downstream manufacturing Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
- G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
- G01D5/2013—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by a movable ferromagnetic element, e.g. a core
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Reciprocating, Oscillating Or Vibrating Motors (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Control Of Linear Motors (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
A constant frequency and amplitude excitation sine wave is imposed on the actuator drive coil 10 through a fixed impedance drive isolation network 18. The amplitude and phase of the voltage across the coil 10 fluctuate depending upon the coil's inductance. This variation in the value of the inductance is dependent upon the change in magnetic flux generated by the coil current supplied from solenoid driver 14 and the air gap between the coil pole and armature 12. Accordingly, by determining coil flux using current sensor 40 a measurable magnitude of displacement can be determined and/or controllably imposed upon a system containing the actuator. Further aspects relate to controlling displacement of the actuator and maintaining cyclically displaceable handling equipment at a desired frequency e.g. by means of a control loop 50. Uses include vibratory finishers and conveyors. <IMAGE>
Description
SENSORLESS MEASUREMENT OF ELECTROMAGNETIC
ACTUATOR DISPLACEMENT DEVICE
FIELD OF THE INVENTION
This invention relates to a method and device to sense and control the displacement of electromagnetic actuators without the use of discrete sensors. The invention may be used to enable a centralized monitoring and control of a multitude of actuators by utilizing a control loop to yield constant displacement under varying load conditions. The invention may additionally or alternatively be used to indicate displacement, without the use of a closed loop control, in which case a manual adjustment may be effected if required.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention there is provided a device for measuring displacement of an electromagnetic actuator, comprising:
a carrier signal generator arranged to superimpose an alternating carrier signal on a drive power supply connected to the actuator;
a detector arranged to detect phase differences between the generated carrier signal and the voltage across the actuator;
a sensor arranged to deduce the magnetic flux generated by the actuator, and
means connected to the sensor and the detector for deriving a signal proportional to the actuator displacement.
The invention also provides a method of measuring displacement of an electromagnetic actuator, comprising the steps of:
superimposing an alternating carrier signal on a drive power supply connected to the actuator;
detecting phase differences between the generated carrier signal and the voltage across the actuator;
deducing the magnetic flux generated by the actuator; and
deriving from the deduced magnetic flux and the detected phase difference a signal proportional to the actuator displacement.
The sensorless measurement of electromagnetic actuator displacement method and device in one embodiment imposes a constant frequency and amplitude excitation sine wave on a solenoid coil through a fixed impedance of a drive isolation network. Compared to the excitation signal, the amplitude and phase of the voltage across the solenoid fluctuate relative to variations in the coil's inductance. The variation or change in inductance is dependent upon the change in magnetic flux density, generated by the solenoid coil current, and the dynamic change (displacement) in air gap between the coil pole face and armature. A signal can be derived that is a function of the displacement by taking into account the effects of the magnetizing force and current.
The effects of the magnetizing force can be accounted for either by sensing the coil current or by taking the displacement readings only when the magnetizing force is zero. After the coil current is sensed, the information is combined with the derived signal to generate a signal that is proportional to the displacement only. In alternative embodiments, displacement can be recorded when the magnetizing current is zero, thus eliminating its effect on the derived signal.
In a further aspect, the invention provides a device comprising means for sensing and controlling displacement of an electromagnetic actuator having a coil and a movable armature, wherein the sensing and controlling means are incorporated in power supply means for the actuator.
In a yet further aspect, the invention provides a method for adjustably maintaining a cyclically displaceable component of process or materials handling equipment substantially at a desired frequency which is variable dependent upon equipment loading conditions, comprising the steps of:
generating a signal proportional to the displacement of the component and using the signal for controlling the displacement to maintain the desired frequency.
Further preferred features of the invention are in the dependent claims. Specific advances, features and advantages of the present invention will become apparent upon examination of the following description and drawings dealing with illustrative embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a block diagram showing interactive and operational sequence of the device.
Figure 2 is an exemplary circuit depicting a phase shift when a carrier signal is supplied to a solenoid through a drive isolation network.
Figure 3 illustrates a typical solenoid driver output wave form which results from a fixed amplitude drive input power line sine wave.
Figure 4 is an exemplary fixed frequency sine wave.
Figure 5 is a typical wave form. It is a resultant of a carrier signal superimposed on the drive power.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment is a device and method in which a constant frequency and voltage amplitude excitation sine wave (carrier) is imparted to a solenoid coil through a fixed impedance of a drive isolation network. The amplitude and phase of the voltage across the solenoid (output), relative to the excitation signal (input), change in relation to the coil's inductance. Accordingly, a desired magnitude of displacement can be controllably imposed upon a system of solenoids. Generally, the present invention may be used to eliminate several problems encountered in material handling equipment, inter alia, such as vibratory finishers and feeders, conveyors and actuators by enabling the measurement and control of displacement in electromagnetic actuators.
One of the critical design and performance parameters in these systems is the control of displacement. Once displacement is made controllable a centralized monitoring circuit can be easily implemented.
One of the many problems which may be addressed by the present invention includes keeping constant product flow under varying load conditions by adjusting the displacement to be compatible with the load. Further, the present invention may be used to enable, for example, a vibratory feeder to be maintained, at its natural resonant frequency to promote maximum system efficiency. Furthermore, the problem of greater power consumption than necessary because of the need to operate the vibrator off its natural resonant frequency as well as the problem of higher material and production costs because the vibrator needs to be larger when it is not being operated at maximum efficiency are eliminated. Displacement signals may be generated to influence downstream process systems which are sensitive to volumetric changes, for example.Flavorings and similar expensive as well as volumetrically critical additives in process systems could thus be monitored closely by the displacement measurement device of the present invention.
Referring now to Figure 1, electromagnetic solenoid 10 is disposed opposite armature 12. Solenoid driver 14 provides drive power via line 15 to electromagnetic solenoid 10. Carrier isolation network 16 insures that the parameters of the carrier signal, i.e. amplitude and phase, are only affected by the varying inductance of electromagnetic solenoid 10. Carrier isolation network 16 could be, for example, a network of passive components forming a parallel resonant circuit wherein the resonance frequency would be set to the carrier frequency. Power connection to solenoid 10 is implemented via drive power and carrier line 17. Drive isolation network 18 is connected through line 17. Further, drive isolation network 18 is a network of passive components forming a voltage divider with or without a clamping diode. Drive isolation network 18 is coupled to carrier power amplifier 24.Carrier generator 26 supplies a carrier signal to solenoid 10 and is connected via carrier power amplifier 24 and drive isolation network 18.
Drive isolation network 28 is coupled to solenoid 10. High pass filter 30 is coupled to drive isolation network 28 and synchronous detector 32. Carrier generator 26 is also connected to synchronous detector 32. Further, current sensor 40 is coupled to drive power line 15 and difference amplifier 42. Difference amplifier 42 is coupled to linearization function 44 which is also connected to low pass filter and amplifier 46. Furthermore, low pass filter and amplifier 46 is connected to output 48 and feedback control system 50. The control loop is completed by connecting feed back control system 50 to solenoid driver 14. A displacement gauge 53 may be coupled to feedback control system 50 to adjust/dial in displacement as apparent. As will be discussed hereinbelow, displacement gauge 53 and associated controls can be used to effectuate a desired acceleration or deceleration of a process system as needed. Armature 12 is integrally attached to a load bearing structure 58, such as a feeder or a conveyor, with support springs 60. Load 62 is supported on platform 64 and mechanical displacement for the structure is designated by "D".
Referring now to Figure 2, a conceptual depiction of a circuit is shown wherein a carrier signal is supplied to a solenoid through a drive isolation network. The figure provides a modular and yet simplified version of some of the significant aspects inherent in the present invention. Drive isolation Network impedance 69 is connected to carrier input 70 in a circuit comprising coil 72 , having coil air gaps "G"; resistor 74; ground 76; and coil capacitor 78 forming a circuit therein with an output terminal 84. Readings taken between input terminals 70 and output terminal 84 provide carrier input wave form 86 and modulated carrier output 88 with wave shift 89 as indicated.
Turning now to Figure 3, a typical wave form is shown.
Ascending and descending wave fronts 90 are portions of a fixed amplitude power line wave.
Figure 4 shows a fixed frequency sine wave 92. This wave is similar to a carrier signal transmitted to solenoid 10.
Figure 5 is a typical wave form having rising and descending wave fronts 94. This is a combination of wave forms from a carrier signal and a power source.
The disclosure hereinabove relates to some of the most important structural features and operational parameters for the sensorless displacement measurement electromagnetic actuator device.
Referring now to Figure 1, solenoid driver 14 supplies driving power to the electromagnetic solenoid 10. It is normally a phase controlled triac or SCR that is operated directly from the power line. The driver may be of type model CC2 controller manufactured by FMC-MHED in Homer City,
PA, U.S.A. The drive power comprises a series of pulses or waves where the leading and trailing edges are rounded off because of the highly reactive nature of solenoid 10. For example, Fig. 3 illustrates a typical wave of a portion of a cycle for a fixed amplitude 50 or 60 hertz power line sine wave. If a vibratory feeder such as load bearing structure 58 is to be operated at its natural frequency, a closed loop system comprising feedback control system 50 with a variable frequency solenoid driver 14 will be needed to control the displacement.Displacement control is one of the possible advances proffered by the present invention. Further, the advances made by the present invention in displacement control enable, if required, the sensing, controlling and monitoring of process equipment to operate at a desired frequency within a desired acceleration and deceleration profile. This feature increases process equipment throughput and efficiency by eliminating manual intervention and guess work. The interaction of feedback control system 50 and solenoid driver 14 will be discussed hereinbelow.
Accordingly, the frequency will be set at the vibratory feeder's (system's) natural resonance frequency which changes with the feeder's loading. It is noteworthy that the natural resonance frequency is dependent upon the type and physical properties such as density and viscosity for example, of the material as well as the feeder's structural organization and components. Thus, the ability to adjust the displacement to any required natural resonance frequency for a variable load and material condition, is one of the significant advances of the present invention when applied to process or material handling equipment. Additionally or alternatively, by controlling the displacement, acceleration, deceleration and braking of a process system can be effectuated.Further, the present invention may be used to provide constant amplitude with varying load conditions and constant amplitude with different trough or structural designs in process equipment.
Referring back to Fig. 1 now, drive power is coupled to solenoid 10 via carrier isolation network 16 to insure that the parameters of the carrier signal, which comprise amplitude and phase are affected only by the varying inductance of the coil of solenoid 10. The electromagnetic solenoid 10 and armature 12 may be, for example, a model FTX1 feeder, manufactured by FMC-MHED, Homer City, PA. Without carrier isolation network 16, the carrier excitation signal would change dramatically as the solenoid drive is turned on and off. Carrier isolation network 16 can be a network of passive components forming a parallel resonant circuit.
Thus, the resonance frequency would be set to the carrier frequency using carrier isolation network 16 by selecting or adjusting the appropriate components. Carrier generator 26 supplies a carrier signal to solenoid 10 in the form of a fixed frequency sine wave as shown in Figure 4. This is a smaller amplitude and much higher frequency signal compared to the drive signal. Accordingly, drive and carrier signals can easily be separated by isolation networks and filters.
Subsequently, carrier power amplifier 24 amplifies the signal generated by carrier generator 26 to a level sufficient to obtain an adequate signal-to-noise ratio at synchronous detector 32. Carrier power is then coupled to solenoid 10 by drive isolation network 18. This insures that the drive signal is not coupled back into carrier power amplifier 24 and prevents damage which is otherwise likely to occur.
Drive isolation network 18 is a network of passive components forming a voltage divider with or without a clamping diode. In the alternate, a network of passive components forming a parallel resonant circuit could be used as a substitute. The resonant frequency is set at or near the frequency of solenoid driver 14. High pass filter 30 attenuates the low frequency drive power component from the voltage developed across solenoid 10. Synchronous detector 32 compares the carrier signal and the high frequency component derived from the solenoid voltage. The output of synchronous detector 32 is proportional to the phase difference between the carrier signal and the high frequency voltage signal developed across solenoid 10. The resultant phase difference is a function of solenoid magnetizing current or magnetic flux density and provides a voltage output at synchronous detector 32.Difference amplifier 42 subtracts out the effects of the solenoid magnetizing current from the output of synchronous detector 32 to produce an output that is proportional to displacement only. Current sensor 40 senses the solenoid magnetizing current generated by the coil of solenoid 10. The relationship between solenoid coil current and the magnetic flux density is nonlinear. Corrections are made to the output of difference amplifier 42 and linearization function 44 is used to effectuate the correction. Linearization function 44 may be in the form of, inter alia, a non-linear function generator, a microprocessor based look-up table or a microprocessor based model of solenoid 10. In the alternate, current sensor 40 may be used as a level sensor and difference amplifier 42 can be operated when the drive current is below a level that would cause an error in the displacement measurement. To integrate this alternate option, difference amplifier 42 incorporates a sample-and-hold circuit to maintain the output of difference amplifier 42 constant when the drive current is above an acceptable level.
Drive isolation network 28 prevents the drive power from solenoid driver 14 from overloading high pass filter 30. Drive isolation network 28 has the same topology as drive isolation network 18. High pass filter 30 is used to further improve signal-to-noise ratio at synchronous detector 32 by reducing the amplitude of the signal of solenoid driver 14 signal which is resident at the input of synchronous detector 32. Low pass filter 46 provides a signal that is proportional to displacement. The signal output from low pass filter 46 is one of the many significant parameters which could be tailored to match with a given system operation.
For example, when used in vibrating feeders, the signal is the controlled displacement output, with feedback control system 50 providing the controlling features. Without feedback control system 50, the system is open loop and display indicator 52 is needed to show the displacement.
Referring now to Fig. 1, when solenoid 10 is energized, armature 12 is displaced. Ultimately load bearing structure 58 and support springs 60 are swayed laterally resulting in platform 64 being displaced a distance "D" as indicated.
Feedback control system 50 enables monitoring and control of displacement "D" so that load bearing structure 58 and bulk product 62, which comprise a system, could be operated at a natural frequency. Thus, the frequency will be set at the system's natural resonance frequency which changes with feeder loading. Further, a desired displacement may be initiated by dialling in the magnitude at displacement gauge 53 to set variable frequency solenoid driver 14 at the desired frequency such that displacement "D" is adjustably set as needed. As discussed hereinabove, displacement gauge 53 may also be used to set a desired deceleration and acceleration profile. Further, power applied in opposite phase to the displacement of the process equipment acceleration may be used to brake, instantly, the equipment thus arresting the displacement to zero through active damping.
Accordingly the described embodiment of the present invention comprises two major components, namely, electromagnetic drive unit with trough or pan and electronic controller with associated control panels. As depicted in
Fig. 2, one of the many preferred aspects of the present invention is the application of a constant frequency and amplitude excitation sine wave (carrier) to a solenoid coil through the fixed impedance of a drive isolation network. In sharp contrast, the current state of the art is to use a single-phase direct-attraction-type AC magnet to induce vibratory motion in electromagnetic vibrators. The magnet has usually a flat-faced armature which is held in position by support springs. Upon application of drive power, the armature is displaced.Generally, in this type of system the solenoid is attached to a trough, pan or bowl and uses the vibratory motion set up by the armature to convey or feed material. Such electromagnetic vibrators are normally driven by an open loop phase controlled SCR or triac and require intensive manual intervention to operate. This makes the current state of the art labour intensive and inefficient.
The present invention may utilize a closed loop control system to yield a constant displacement or to maintain resonance under varying load conditions. As discussed hereinabove, a more uniform product flow and increased efficiency is achieved by eliminating manual operation and automatically operating the system at near the natural resonant frequency of the system. It should be noted that displacement is controlled by drive amplitude irrespective of system frequency. However, a secondary control loop, such as feedback control system 50 configured with low pass filter 46, can be used to maintain the system at its natural resonant frequency. Further, the present invention enables an optional controller to be placed under the governance of a host computer that would make the necessary changes in material flow to be congruent with a predetermined displacement magnitude and frequency. This feature provides significant flexibility in operation and promotes system efficiency.
While a preferred embodiment of the sensorless displacement measurement electromagnetic actuator device has been shown and described, it will be appreciated that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims. Thus, although maintaining a driving actuator at a variable resonant frequency has been specifically described, the invention may also be used to maintain a cyclically driven magnetic actuator at other desired frequencies, for example to avoid resonance in applications where this is required, or to provide specified product flow rates in a vibratory feeder.
Claims (33)
1. A device for measuring displacement of an electromagnetic actuator, comprising:
a carrier signal generator arranged to superimpose an alternating carrier signal on a drive power supply connected to the actuator;
a detector arranged to detect phase differences between the generated carrier signal and the voltage across the actuator;
a sensor arranged to deduce the magnetic flux generated by the actuator; and
means connected to the sensor and the detector for deriving a signal proportional to the actuator displacement.
2. A device as defined in claim 1 wherein the carrier signal has a substantially constant frequency, substantially constant amplitude alternating voltage.
3. A device as defined in claim 2 wherein the carrier signal is of sinusoidal form.
4. A device as defined in any preceding claim wherein the sensor senses the current supplied to the actuator.
5. A device as defined in any preceding claim wherein the drive power supply is connected to the actuator via a carrier signal isolation network.
6. A device as defined in any preceding claim wherein the carrier signal generator is connected to the actuator via a drive isolation network.
7. A device as defined in any preceding claim wherein the detector is connected to the actuator via a drive isolation network.
8. A device as defined in any preceding claim wherein the detector is connected to the actuator via a high pass filter.
9. A device as defined in any preceding claim wherein the displacement signal deriving means is arranged to operate when the actuator flux is sufficiently low so as to leave the detected phase difference dependent substantially upon actuator displacement alone.
10. A device as defined in any of claims 1-8 wherein the displacement signal deriving means is arranged to subtract from the output of the phase difference detector a signal derived from the sensor thereby to render the output from the displacement signal deriving means dependent substantially upon actuator displacement alone.
11. A device as defined in any preceding claim, wherein the displacement signal deriving means is connected to linearising means.
12. A device as defined in any preceding claim1 wherein the displacement signal deriving means is connected to a low-pass filter.
13. A device as defined in any preceding claim, wherein the displacement signal is used by a feedback control arrangement for regulating the amplitude of displacement of the electromagnetic actuator.
14. A device as defined in any of claims 1-12 wherein the displacement signal is used by a feedback control arrangement to maintain a cyclically driven system substantially at its resonant frequency.
15. A device as defined in claim 14 wherein the resonant frequency is variable.
16. A vibratory materials handling or processing system incorporating a device as claimed in any of claims 1-15.
17. A method of measuring displacement of an electromagnetic actuator, comprising the steps of:
superimposing an alternating carrier signal on a drive power supply connected to the actuator;
detecting phase differences between the generated carrier signal and the voltage across the actuator;
deducing the magnetic flux generated by the actuator; and
deriving from the deduced magnetic flux and the detected phase difference a signal proportional to the actuator displacement.
18. A method as defined in claim 17 wherein the magnetic flux generated by the actuator is deduced from the current supplied to the actuator.
19. A method as defined in claims 17 or 18 wherein the signal proportional to displacement is derived when the actuator flux is sufficiently low so as to leave the detected phase difference dependent substantially upon actuator displacement alone.
20. A method as defined in claims 17 or 18 wherein the signal proportional to displacement is derived by subtracting from the detected phase difference a signal derived from the magnetic flux.
21. A method as defined in any of claims 17-20, wherein the signal proportional to actuator displacement is used to control materials handling or processing equipment for accelerating, decelerating or braking said equipment.
22. A method as defined in any of claims 17-20 wherein the signal proportional to actuator displacement is used in a feedback control arrangement to maintain a cyclically driven system substantially at its resonant frequency.
23. A device comprising means for sensing and controlling displacement of an electromagnetic actuator having a coil and a movable armature, wherein the sensing and controlling means are incorporated in power supply means for the actuator.
24. A device according to claim 23 wherein the power supply means includes an electronic network.
25. A device according to claim 23 or 24 wherein the armature is attached to a process machine or a materials handling machine.
26. A device according to any of claims 23-25 wherein the power supply means includes a feedback control loop.
27. A method for adjustably maintaining a cyclically displaceable component of process or materials handling equipment substantially at a desired frequency which is variable dependent upon equipment loading conditions, comprising the steps of:
generating a signal proportional to the displacement of the component and using the signal for controlling the displacement to maintain the desired frequency.
28. A method as claimed in claim 27 wherein the desired frequency is a resonant frequency of the equipment.
29. A method as claimed in claim 27 or 28 wherein the component comprises a driven armature attached to a resiliently mounted portion of the equipment.
30. A method as claimed in any of claims 27-29 used to control material flow, separation or admixing in a process or materials handling equipment system.
31. A method as claimed in any of claims 27-30 used to control acceleration, deceleration or braking of the equipment.
32. A device for measuring displacement of an electromagnetic actuator substantially as described with reference to or as shown in the drawings.
33. A method for measuring displacement of an electromagnetic actuator substantially as described with reference to the drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21447994A | 1994-03-17 | 1994-03-17 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9504314D0 GB9504314D0 (en) | 1995-04-19 |
| GB2287542A true GB2287542A (en) | 1995-09-20 |
| GB2287542B GB2287542B (en) | 1998-07-08 |
Family
ID=22799230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9504314A Expired - Fee Related GB2287542B (en) | 1994-03-17 | 1995-03-03 | Sensorless measurement of electromagnetic actuator displacement device |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5841621A (en) |
| JP (1) | JP3851362B2 (en) |
| AU (1) | AU695997B2 (en) |
| CA (1) | CA2143768C (en) |
| ES (1) | ES2107948B1 (en) |
| GB (1) | GB2287542B (en) |
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| EP0723137A1 (en) * | 1995-01-17 | 1996-07-24 | Eaton Corporation | Two wire position sense and control of modulating gas valve or other electromechanical actuators |
| GB2333132A (en) * | 1997-08-02 | 1999-07-14 | Lucas Ind Plc | Spill valve control method. |
| WO2002033227A1 (en) * | 2000-10-20 | 2002-04-25 | Micro-Epsilon Messtechnik Gmbh & Co. Kg | Device and method for detecting the position of an object |
| WO2002066931A1 (en) * | 2001-02-23 | 2002-08-29 | Robert Bosch Gmbh | Sensor arrangement for detecting the position of an electromagnetically displaced armature |
| EP1288449A1 (en) * | 2001-08-29 | 2003-03-05 | Micro-Epsilon Messtechnik GmbH & Co. KG | Device and method for detecting the position of an object |
| WO2006027462A1 (en) * | 2004-08-27 | 2006-03-16 | Johnson Controls Technology Company | Equipment control device for providing information about an operating state of the equipment |
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| DE29721054U1 (en) * | 1997-12-01 | 1999-04-01 | Meteor Gummiwerke K. H. Bädje GmbH & Co, 31167 Bockenem | Movable window element |
| US6233132B1 (en) | 1998-09-03 | 2001-05-15 | Ranco Incorporated Of Delaware | Zero cross relay actuation method and system implementing same |
| US6150778A (en) * | 1998-11-04 | 2000-11-21 | Tridelta Industries, Inc. | Sensorless rotor position detection for switched reluctance machines having irregular poles |
| US6246193B1 (en) | 1999-08-26 | 2001-06-12 | Tridelta Industries, Inc. | Encoderless rotor position detection method and apparatus |
| US6262620B1 (en) | 1999-11-02 | 2001-07-17 | Ranco Incorporated Of Delaware | Driver circuitry for latching type valve and the like |
| GB0006144D0 (en) * | 2000-03-14 | 2000-05-03 | Isis Innovation | Position and electromagnetic field sensor |
| JP4840727B2 (en) * | 2006-08-04 | 2011-12-21 | 横河電機株式会社 | Planar positioning device |
| US8007247B2 (en) * | 2007-05-22 | 2011-08-30 | Medtronic, Inc. | End of stroke detection for electromagnetic pump |
| WO2011154785A2 (en) * | 2010-06-10 | 2011-12-15 | パナソニック電工株式会社 | Position sensor |
| EP3084456B1 (en) * | 2013-12-23 | 2018-01-31 | Allegro Microsystems, LLC | Magnetic field sensor and method for sensing relative location of the magnetic field sensor and a target object along a movement line |
| US9869566B2 (en) | 2016-02-12 | 2018-01-16 | Allegro Microsystems, Llc | Angle sensing using differential magnetic measurement and a back bias magnet |
| US10323958B2 (en) | 2016-03-18 | 2019-06-18 | Allegro Microsystems, Llc | Assembly using a magnetic field sensor for detecting a rotation and a linear movement of an object |
| US10008457B2 (en) * | 2016-10-18 | 2018-06-26 | Semiconductor Components Industries, Llc | Resonance-coupled signaling between IC modules |
| US11473935B1 (en) | 2021-04-16 | 2022-10-18 | Allegro Microsystems, Llc | System and related techniques that provide an angle sensor for sensing an angle of rotation of a ferromagnetic screw |
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| GB2044461A (en) * | 1979-03-16 | 1980-10-15 | Moog Inc | Armature position detector |
| GB2132362A (en) * | 1982-12-27 | 1984-07-04 | Varian Associates | High resolution position sensing apparatus |
| GB2213594A (en) * | 1987-12-09 | 1989-08-16 | Herion Werke Kg | Apparatus for measuring the position of the armature of a coil-and-armature magnetic device |
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| BE831952A (en) * | 1975-07-31 | 1976-02-02 | Acec | METHOD OF MEASURING THE POSITION OF A MAGNETIC ROD, PARTICULARLY OF AN ADJUSTING BAR OF A NUCLEAR REACTOR |
| US4659969A (en) * | 1984-08-09 | 1987-04-21 | Synektron Corporation | Variable reluctance actuator having position sensing and control |
| DE3625273A1 (en) * | 1986-07-25 | 1988-02-04 | Bosch Gmbh Robert | Electrical displacement sensor |
| US4970622A (en) * | 1986-12-03 | 1990-11-13 | Buechl Josef | Method and apparatus for controlling the operation of an electromagnet |
| US5293551A (en) * | 1988-03-18 | 1994-03-08 | Otis Engineering Corporation | Monitor and control circuit for electric surface controlled subsurface valve system |
| US4851959A (en) * | 1988-07-25 | 1989-07-25 | Eastman Kodak Company | Solenoid engagement sensing circuit |
| US5172298A (en) * | 1990-01-09 | 1992-12-15 | Honda Giken Kogyo Kabushiki Kaisha | Electromagnetic actuator |
| US5206540A (en) * | 1991-05-09 | 1993-04-27 | Unitrode Corporation | Transformer isolated drive circuit |
| US5196983A (en) * | 1991-10-07 | 1993-03-23 | Eastman Kodak Company | Solenoid engagement sensing circuit |
| US5481187A (en) * | 1991-11-29 | 1996-01-02 | Caterpillar Inc. | Method and apparatus for determining the position of an armature in an electromagnetic actuator |
| EP0549911B1 (en) * | 1992-01-03 | 1997-01-29 | British Nuclear Fuels PLC | Apparatus for monitoring inductance |
| US5539608A (en) * | 1993-02-25 | 1996-07-23 | Eaton Corporation | Electronic interlock for electromagnetic contactor |
-
1995
- 1995-03-02 CA CA002143768A patent/CA2143768C/en not_active Expired - Fee Related
- 1995-03-03 GB GB9504314A patent/GB2287542B/en not_active Expired - Fee Related
- 1995-03-15 ES ES09500516A patent/ES2107948B1/en not_active Expired - Lifetime
- 1995-03-16 AU AU14905/95A patent/AU695997B2/en not_active Ceased
- 1995-03-17 JP JP08448495A patent/JP3851362B2/en not_active Expired - Fee Related
-
1996
- 1996-06-04 US US08/659,066 patent/US5841621A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2044461A (en) * | 1979-03-16 | 1980-10-15 | Moog Inc | Armature position detector |
| GB2132362A (en) * | 1982-12-27 | 1984-07-04 | Varian Associates | High resolution position sensing apparatus |
| GB2213594A (en) * | 1987-12-09 | 1989-08-16 | Herion Werke Kg | Apparatus for measuring the position of the armature of a coil-and-armature magnetic device |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0723137A1 (en) * | 1995-01-17 | 1996-07-24 | Eaton Corporation | Two wire position sense and control of modulating gas valve or other electromechanical actuators |
| GB2333132A (en) * | 1997-08-02 | 1999-07-14 | Lucas Ind Plc | Spill valve control method. |
| WO2002033227A1 (en) * | 2000-10-20 | 2002-04-25 | Micro-Epsilon Messtechnik Gmbh & Co. Kg | Device and method for detecting the position of an object |
| US6762922B2 (en) | 2000-10-20 | 2004-07-13 | Micro-Epsilon Messtechnik Gmbh & Co. Kg | Device and method for detecting the position of an object |
| WO2002066931A1 (en) * | 2001-02-23 | 2002-08-29 | Robert Bosch Gmbh | Sensor arrangement for detecting the position of an electromagnetically displaced armature |
| EP1288449A1 (en) * | 2001-08-29 | 2003-03-05 | Micro-Epsilon Messtechnik GmbH & Co. KG | Device and method for detecting the position of an object |
| WO2006027462A1 (en) * | 2004-08-27 | 2006-03-16 | Johnson Controls Technology Company | Equipment control device for providing information about an operating state of the equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| AU1490595A (en) | 1995-09-28 |
| US5841621A (en) | 1998-11-24 |
| CA2143768C (en) | 1999-12-14 |
| JP3851362B2 (en) | 2006-11-29 |
| ES2107948A1 (en) | 1997-12-01 |
| GB2287542B (en) | 1998-07-08 |
| GB9504314D0 (en) | 1995-04-19 |
| AU695997B2 (en) | 1998-08-27 |
| JPH07288995A (en) | 1995-10-31 |
| ES2107948B1 (en) | 1998-06-16 |
| CA2143768A1 (en) | 1995-09-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |